In general terms, a standard radiator contains a vertical or horizontal finned tubing section connected between two tanks. It is designed to hold an abundant amount of water and ethylene glycol, or antifreeze, and circulates through the car's grille in discreet passages that contact with the atmosphere to cool the liquid. Because of this process, heat is conducted away from the engine parts allowing smooth performance of the engine. The outside air that passes through the radiator grille helps to cool the liquid, which then circulates back to the engine by means of another hose.

The radiator reduces the temperature of the coolant, which has absorbed the heat from the engine, keeping it within a normal operating temperature. It is vitally important that you check your radiator regularly. Overheating an engine can cause permanent damage. A leaking radiator will cause your engine to run at a higher than normal temperature and may cost you huge dollars in engine repair costs. A radiator should always be completely filled with water, antifreeze/coolant or a mixture thereof. Allowing the presence of air pockets in the radiator will produce more internal pressure than liquid coolant because gases expand under heat tremendously more than liquids, and high pressure also results in higher operating temperatures.

The radiator can also accumulate internal residue and/or corrode over time. The cooling efficiency can be dramatically reduced as a result. If you find your vehicle is running at higher than normal temperatures, it may be time to install a new replacement or high performance radiator.

1. Water Pump
   A water pump is the central reason your vehicle runs at a normal operating temperature. An overheating car is not something that anyone ever wants to deal with. Your water pump is of primary importance to your vehicle’s coolant circulation throughout your vehicle's cooling system. If your water pump isn't operating, the engine coolant just sits in the block and heads. It doesn’t circulate or flow to the radiator to displace its heat. No coolant heat displacement from the radiator means your vehicle will quickly overheat. This will lead to costly damage such as blown head gaskets or even irreversible damage such as warped heads and perhaps a blown engine. Even a reduction in pressure delivered by the water pump can lead to costly damage to your vehicle. Constricted or blocked flow leads to higher engine operating temperatures. Overheating can damage the components of your cooling system as well such as the thermostat, radiator, hoses etc. If you are replacing your water pump, it is wise to do a complete cooling system tune-up. Don’t forget the other vital parts like hoses, thermostats, radiator caps and fan belts. Also remember that not all water pumps are the same. The water pump is unique to your model of vehicle and has been designed strictly for your engine cooling efficiency. High performance and custom water pumps go above and beyond to deliver the optimum cooling performance.
   
   
2. Thermostat
   The thermostat in a vehicle regulates the flow of coolant throughout the system. This is important for two reasons. First, it controls the amount of coolant moving through the cooling system to help keep the vehicle’s engine from overheating. And second, it controls the flow in such a way that the operating temperature is kept within a narrow margin. Your vehicle’s engine operates at peak efficiency within this narrow band of temperature regulation. In other words, you don’t want your engine running too hot or too cold.
   
   
3. Heater Core
   A Heater Core provides the hot air that comes out of heater vents in your vehicle. You may wonder what this has to do with cooling systems. Heating and cooling are really very closely related. After all, cooling is simply the transference or separation of the heat energy from the object in which you are trying to cool off. Temperature is really a measurement of how fast molecules vibrate, or how much energy they have. Trying to slow the vibration is less efficient than separating the energy from the quickly vibrating molecules from the slower ones.

The heater core is more or less a small radiator usually located under the dashboard. Coolant fluid is circulated from the main engine radiator to the heater core, but only when you turn the vehicle’s heater on. The internal heater control unit opens or closes a valve that meters the flow of coolant fluid to the heater core. That allows heat to radiate from the heater core. This is why your vehicle runs cooler when you have the heater on. The fin-like configuration of the heater core permits hot air passage into the vehicle. The hot fluid transfers its heat to the air through the fins and into the interior of your vehicle. When the heater core channels become restricted or plugged, the flow of hot liquid slows or stops.

This, in turn, reduces or even eliminates the heat transfer efficiency to the flow of air and your vehicles’ heater doesn’t work very well. Flushing the radiator and heater core can sometimes improve the flow of liquid to the heater core, but replacement is usually a better option. A sweet, burning smell inside your vehicle when the heater fan is operating is a telltale sign of heater core problems. Another indicator is that the inside of your windows fog up when the heat is turned on. This is due to condensation built up from the blockage or restriction. The heater core is a significant component of the unrestricted air/heat/cooling system circulation assembly that provides heat and cooling.